Many herbicides require the addition of an adjuvant to the spray mixture to provide wetting and spreading on foliar surfaces. Often that adjuvant is a surfactant, which can perform a variety of functions, such as increasing spray droplet retention on difficult to wet leaf surfaces, or to provide penetration of the herbicide into the plant cuticle. These adjuvants are provided either as a tankside additive or used as a component in herbicide formulations.
Gaskin, et al., Pestic. Sci. 1993, 38, 185-192, demonstrated that some trisiloxane ethoxylates (TSE), such as Silwet L-77(copyright) surfactant (available from Witco Corp. of Greenwich, Conn.), can antagonize cuticular penetration of a herbicide into grasses, when compared to the herbicide alone. The term antagonism is used to indicate that the treatment of herbicide plus adjuvant is less effective than the comparative herbicide treatment.
Sandbrink, et al., (Pest. Sci. 1993, 38, 272-273, published that a TSE antagonized glyphosate performance relative to glyphosate alone in the control of Panicum maximum Jacq. Snow, et al., Langmuir, 1993, 9, 424-30, discusses the physical properties and synthesis of novel cationic siloxane surfactants. These siloxanes are based on the reaction of chloro propyl modified trisiloxane with an alkanolamine, such as N-methylethanolamine, which was further reacted with a halide to make a quaternary surfactant.
Petroff, et al., EP 92116658, describes the use of cationic, quaternary trisiloxanes to enhance the efficacy of glyphosate on velvetleaf, a broadleaf weed. Henning, et al., (DE 4318537) describes cationic siloxanyl modified polyhydroxy hydrocarbon or carbohydrate for use with plant protection agents. These compounds are derived from a saccharide containing 1 to 10 pentose and/or hexose units, modified with a quaternary ammonium group, and a siloxane moiety.
Reid, et al., U.S. Pat. No. 3,389,160 describes amino modified siloxane alkoxylates where the amino functionality appears as the terminal group on the alkyleneoxide moiety, opposite the siloxane group.
Policello in U.S. Pat. No. 5,998,331 discloses amino modified siloxanes wherein the amine is bound by an ether bond to the siloxane backbone wherein the amine may be terminal or pendant to the backbone.
It has now been discovered that an organosiloxane copolymer containing separate terminal or pendant amino-containing and polyether-containing functional groups are useful as adjuvants and additives for applications with herbicides.
Optionally, the modified organosiloxanes of this invention may be blended with conventional trisiloxane alkoxylates (TSAs). Blends of these modified organosiloxanes with TSAs provide enhanced wetting properties on difficult to wet plant surfaces.
Additionally the modified organosiloxanes of this invention may be blended with conventional organic surfactants, as emulsifiers, dispersants, coadjuvants or cosurfactants.
The modified organosiloxanes are useful as adjuvants for herbicide applications.
Modified Organosiloxanes:
The modified organosiloxanes of the present invention preferably are amino polyether siloxanes and have the average general formula:
[Oxc2xdMe2SiOxc2xd]d[Oxc2xdMeSi(Z)Oxc2xd]e[Oxc2xdSiMe(Q)Oxc2xd]f[Oxc2xdSiMe2P]g
where d is 0 to 2; e is  greater than 0 and  less than 4, preferably  greater than 0 to 2; fxe2x89xa70 and  less than 4, most preferably  greater than 0 to 2; g is 2 if the siloxane is not cyclic or zero if the siloxane is cyclic; d+e+f+gxe2x89xa66; Z=CnH2nO(CaH2aO)wR1; n=2 to 4, preferably 3; a=2-4, preferably 2; w=1 to 30; R1 is hydrogen, or a hydrocarbon radical between 1 and 4 carbon atoms; Q=B(O)jR2N(R3)2; B is a divalent bridging group of C1 to C6, preferably C3 to C4; R2 is a divalent organic group containing 2 to 8 carbons, preferably 3 to 4 carbons, each optionally OH substituted; j is 0 or 1, preferably 1; R3 is hydrogen, an amino alkyl of one to four carbons, an alkyl of 2 to 4 carbon atoms, an alkyl of 2 to 4 carbon atoms substituted with one or more hydroxy groups or a polyether of the general structure xe2x80x94(CaH2aO)bR4; each a is 2 to 4, preferably 2 to 3; each b is 2 to 30, preferably 2 to 8; the R4 groups independently are hydrogen or a group of 1 to 4 carbons; and P is Q or, provided f is not 0, methyl.
Preferably a is such that there is a mixture of ethylene oxide (EO), propylene oxide (PO) units and butylene oxide (BuO) units, where a=2 and 4. Preferably, for aqueous applications, there is a preponderance of EO units, most preferably every a=2. For non-aqueous applications, such as crop oil concentrates, there may be more PO and BuO units. When Z or R3 contain a mixture of oxyalkylenes, the different oxyalkylene groups may be arranged in blocked or random manner. One skilled in the art will understand the advantages in the position of the oxyethylene relative to the oxypropylene, when the alkyleneoxide group is blocked.
The Q groups may include protonated amines, i.e., where there is a hydrogen atom attached to the nitrogen in the Q group, which can occur to the aminosilicon alkoxylates under acidic conditions. Also contemplated herein are quaternary versions of Q, i.e., where there is a third R3 group on the nitrogen in Q. Quaternarization may be accomplished in conventional manner. In either such case, i.e., protonated or quaternarized Q, the group Q may be represented by the formula:
B(O)jR2N+(R3)3. 
In addition, the compositions of the present invention optionally may include TSAs of the general formula:
R5Me2SiO[MeSi(G)O]xSiMe2R5
Wherein x=0 to 2, preferably 1; G=CnH2nO(C2H4O)t(C3H6O)wR6; n=2 to 4, preferably 3; t=3 to 20, preferably 4 to 8; w=0 to 8, providing that when w is  greater than 0, (t+w) is preferably between 5 and 12; R6 is hydrogen, acetyl or a hydrocarbon radical between 1 and 4 carbon atoms; and R5 is G, or an alkyl of one to four carbons. The preferred nonionic siloxane alkyoxylates are trisiloxane alkoxylates, where x=1, n=3, t=4 to 8, w=0, R5 is Me, R6 is H or Me.
The compositions of the present invention also optionally include pesticides, especially acid functionalized ones, i.e., compounds that contain at least one carboxylic, sulfonic or phosphonic acid group or their salt or ester. The term pesticide means any compound used to destroy pests, e.g., rodenticides, fungicides, and herbicides. Illustrative examples of pesticides which can be employed include, but are not limited to, growth regulators, photosynthesis inhibitors, pigment inhibitors, mitotic disrupters, lipid biosynthesis inhibitors, cell wall inhibitors, and cell membrane disrupters. The amount of pesticide employed in compositions of the invention varies with the type of pesticide employed. More specific examples of pesticide compounds that can be used with the compositions of the invention are: phenoxy acetic acids, phenoxy propionic acids, phenoxy butyric acids, benzoic acids, triazines and s-triazines, substituted ureas, uracils, bentazon, desmedipham, methazole, phenmedipham, pyridate, amitrole, clomazone, fluridone, norflurazone, dinitroanilines, isopropalin, oryzalin, pendimethalin, prodiamine, trifluralin, glyphosate, sulfonylureas, imidazolinones, clethodim, diclofop-methyl, fenoxaprop-ethyl, fluazifop-p-butyl, haloxyfop-methyl, quizalofop, sethoxydim, dichlobenil, isoxaben, and bipyridylium compounds.
The compositions also may include fatty acid esthers, e.g., methyl soyate, for crop oil concentrate formulations, as well as water, for aqueous applications. Buffers, preservatives and other standard excipients known in the art also may be included in the composition. When the compositions of the present invention are insoluble in distilled water, spreading may be achieved by the addition of a small amount of an acid, such as acetic acid, to protonate the amine functionality, thereby increasing water solubility. Moreover, other cosurfactants which do not interfere with superspreading, may be included, for instance cosurfactants which have short chain hydrophobes (C10 or less, not counting any branching carbons) or alkyleneoxide copolymers such as sold under the trademarks PLURONIC(copyright) and TETRONIC(copyright) (both BASF Corp.) and UCON(copyright) (Union Carbide/Dow Corp). Examples of such cosurfactants and their use can be found in U.S. Pat. No. 5,104,647, U.S. Pat. No. 5,558,806 and EP 0862857, all incorporated herein by reference.
The modified organosiloxanes of the present invention may be made by the hydrosilation of a hydridosiloxane with an epoxy intermediate, such as allyl glycidyl ether, vinyl cyclohexene monoxide, along with an allyl polyalkyleneoxide, which may be reacted sequentially, or as a premix of the epoxy and allyl polyalkyleneoxide intermediates. This is followed by ring opening the epoxide with the appropriate amino group. The hydridosoxanes described are commercially available and may be made as known in the art. Hydrosilation conditions are within the general conditions taught in Marciniec (Comprehensive Handbook of Hydrosilylation, Edited by Bogdan Marciniec, Pergamon Press).
Instead of an epoxy ring opening, it is also possible to prepare an amino polyether silicone useful in the invention by hydrosilating both an unsaturated amine such as methallyl amine, N-allyl-N, N-dimethylamine, N-allyl-N, N-diethylamine, N-allyl-N-methylamine and an unsaturated polyether, simultaneously or sequentially, to give a product as described above, where j is 0.
The nonionic siloxane and the pesticides are commercially available and their manufacture is known in the art.
The modified organosiloxanes may be used in agricultural applications as adjuvants for pesticides, wherein the siloxane is applied in a pesticide formulation to agricultural products. The composition of the present invention is useful as a tankside additive, or as a component in a herbicide formulation. In addition the compositions of the present invention are useful as adjuvants for other pesticides, such as, fungicides, insecticides, plant growth regulators, acaracides and the like. The pesticide formulations may be wet, dry, slurries or other formulations as are known in the art.
The siloxanes are added directly to a spray tank along with an acid functional pesticide, or as part of a pesticide formulation. When used as a tankside additive, the siloxane is present at weight concentrations between 0.001% and 5.0%, preferably between 0.025% and 0.5%. Likewise, when the modified organosiloxanes are used in a pesticide formulation (In-can), they are present at weight concentrations that will deliver between 0.001% and 5.0% to the final use dilution, preferably between 0.025% and 0.5%, of the final use dilution.
It is noted that most dilutions will be made with water, but in the case of crop oil concentrates, oils (mineral, silicone, animal or vegetable oils) will be the diluents.
When the compositions of the present invention are used in conjunction with a TSA, the weight ratio of the TSA to the modified organosiloxanes is between 5:95 and 95:5, preferably between 5:95 and 40:60. The blend may be accomplished by mixing physically the two components prior to use, or by adding them separately to a spray mixture at the point of use.
When the compositions of the present invention are used in conjunction with nonsilicone surfactants, the weight ratio of the nonsilicone surfactant to the modified organosiloxane is between 1:99 and 99:1, preferably between 99:1 and 40:60.
The modified organosiloxanes also may be used generally as surface active agents in aqueous formulation where there is an acid functionalized component. The modified organosiloxanes also may be used as surface active agents, including, but not limited to, as surfactants, wetting agents and softeners for textiles, flow and leveling agents in coatings, hair care products, skin care and creams for personal care applications and anti-static agents, detergents and softeners for laundry products.
The invention is illustrated by the following non-limiting examples.